Effects of Strain Rate Change on Fatigue Life of Carbon Steel in High-Temperature Water

Effects of Strain Rate Change on Fatigue Life of Carbon Steel in High-Temperature Water PDF Author: Y. Asada
Publisher:
ISBN:
Category : Carbon steel
Languages : en
Pages : 16

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Book Description
In high temperature waters that contain dissolved oxygen (DO) to certain content, the fatigue life of carbon steel is strongly affected by strain rate. A formula has been advanced to quantify this effect when the strain rate is held constant. However, the strain rate changes continuously in most of transients of actual plant operation. There is no way currently to assess the effects of strain rate when the strain rate is varied as in the actual plant transients. To find a solution to this problem, a series of strain controlled fatigue tests have been conducted with the strain rate changed stepwise or continuously. It is shown that a method, in which the product of the environmental effect and the strain increment within a unit time interval in a transient period is integrated from the minimum strain to the maximum, evaluates the environmental effect with satisfactorily high accuracy. This method is called the modified rate approach method. It is shown also that the procedure of taking the strain rate as averaged over the minimum to peak of the strain change as giving rise to more conservative evaluations than the ones the modified rate approach method produces.

Effects of Strain Rate Change on Fatigue Life of Carbon Steel in High-Temperature Water

Effects of Strain Rate Change on Fatigue Life of Carbon Steel in High-Temperature Water PDF Author: Y. Asada
Publisher:
ISBN:
Category : Carbon steel
Languages : en
Pages : 16

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Book Description
In high temperature waters that contain dissolved oxygen (DO) to certain content, the fatigue life of carbon steel is strongly affected by strain rate. A formula has been advanced to quantify this effect when the strain rate is held constant. However, the strain rate changes continuously in most of transients of actual plant operation. There is no way currently to assess the effects of strain rate when the strain rate is varied as in the actual plant transients. To find a solution to this problem, a series of strain controlled fatigue tests have been conducted with the strain rate changed stepwise or continuously. It is shown that a method, in which the product of the environmental effect and the strain increment within a unit time interval in a transient period is integrated from the minimum strain to the maximum, evaluates the environmental effect with satisfactorily high accuracy. This method is called the modified rate approach method. It is shown also that the procedure of taking the strain rate as averaged over the minimum to peak of the strain change as giving rise to more conservative evaluations than the ones the modified rate approach method produces.

Effects of the Environment on the Initiation of Crack Growth

Effects of the Environment on the Initiation of Crack Growth PDF Author: William Alan Van der Sluys
Publisher: ASTM International
ISBN: 0803124082
Category : Metals
Languages : en
Pages : 304

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Fatigue of Carbon and Low-alloy Steels in LWR Environments

Fatigue of Carbon and Low-alloy Steels in LWR Environments PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 23

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Book Description
Fatigue tests have been conducted on A106-Gr B carbon steel and A533-Gr B low-alloy steel to evaluate the effects of an oxygenated-water environment on the fatigue life of these steels. For both steels, environmental effects are modest in PWR water at all strain rates. Fatigue data in oxygenated water confirm the strong dependence of fatigue life on dissolved oxygen (DO) and strain rate. The effect of strain rate on fatigue life saturates at some low value, e.g., between 0.0004 and 0.001%/s in oxygenated water with (approximately)0.8 ppm DO. The data suggest that the saturation value of strain rate may vary with DO and sulfur content of the steel. Although the cyclic stress-strain and cyclic-hardening behavior of carbon and low-alloy steels is distinctly different, the degradation of fatigue life of these two steels with comparable sulfur levels is similar. The carbon steel exhibits pronounced dynamic strain aging, whereas strain-aging effects are modest in the low-alloy steel. Environmental effects on nucleation of fatigue crack have also been investigated. The results suggest that the high-temperature oxygenated water has little or no effect on crack nucleation.

Materials Ageing in Light-Water Reactors

Materials Ageing in Light-Water Reactors PDF Author: François Cattant
Publisher: Springer Nature
ISBN: 3030856003
Category : Technology & Engineering
Languages : en
Pages : 2448

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Book Description
This book is an extensive and detailed guide to the subject of materials ageing in light-water nuclear reactors. Proper management of materials degradation is essential for the safe, reliable, and economic operation of nuclear power plants across the globe. This handbook features a stunning and thorough observational treatment of the key materials degradational phenomena in light-water reactors, capturing the results of some typical destructive examinations that have been carried out to understand and furthermore mitigate these failures. It provides a comprehensive collection of unique photographs, detailed schematics, concise analyses, as well as precise measurements and expert recommendations. It is organized in such a manner that engineers and scientists can use the observations presented to not only arrive at their own conclusions but also subsequently improve their knowledge of specific materials ageing issues. This handbook is supported by the Materials Ageing Institute (MAI) and Électricité de France (EDF) and is an extensive update to the previous edition, featuring up-to-minute information to reflect the state of the art as of 2020. Since its founding in 2008, the MAI has succeeded in expanding its membership and today represents two-thirds of the world's installed nuclear power capacity, benefiting from nearly 5,000 years of combined experience in reactor operation. The vast archive of past observational data and world-leading expert recommendations presented in this handbook leverage the unique expertise of the MAI in studying the key degradation phenomena of materials to ensure the secure and sustainable operation of carbon-free electricity production. It is a must-have on the desks of any engineers or researchers involved in ageing management for light-water reactors.

Fatigue and Crack Growth

Fatigue and Crack Growth PDF Author: Sumio Yukawa
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 340

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Proceedings of the International Topical Meeting on Probabilistic Safety Assessment

Proceedings of the International Topical Meeting on Probabilistic Safety Assessment PDF Author:
Publisher:
ISBN:
Category : Factories
Languages : en
Pages : 694

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Evaluation of Effects of LWR Coolant Environments on Fatigue Life of Carbon and Low-Alloy Steels

Evaluation of Effects of LWR Coolant Environments on Fatigue Life of Carbon and Low-Alloy Steels PDF Author: OK. Chopra
Publisher:
ISBN:
Category : Carbon steel
Languages : en
Pages : 20

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Book Description
The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Figure I-90 of Appendix I to Section III of the Code specifies fatigue design curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Recent test data indicate a significant decrease in fatigue life of carbon and low-alloy steels in LWR environments when five conditions are satisfied simultaneously, viz., applied strain range, temperature, dissolved oxygen in the water, and sulfur content of the steel are above a minimum threshold level, and the loading strain rate is below a threshold value. Only a moderate decrease in fatigue life is observed when any one of these conditions is not satisfied. This paper summarizes available data on the effects of various material and loading variables such as steel type, dissolved oxygen level, strain range, strain rate, and sulfur content on the fatigue life of carbon and low-alloy steels. The data have been analyzed to define the threshold values of the five critical parameters. Methods for estimating fatigue lives under actual loading histories are discussed.

Understanding and Predicting Material Degradation

Understanding and Predicting Material Degradation PDF Author: Raj Mohan
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 206

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Progress Reports

Progress Reports PDF Author: Welding Research Council (U.S.)
Publisher:
ISBN:
Category : Welding
Languages : en
Pages : 634

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Proceedings of the ASME Pressure Vessels and Piping Conference--2006: Codes and standards

Proceedings of the ASME Pressure Vessels and Piping Conference--2006: Codes and standards PDF Author:
Publisher:
ISBN:
Category : Aeroelasticity
Languages : en
Pages : 612

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Book Description